The Great Pagoda at Kew Gardens in London has been returned to its 18th-century splendour and will re-open this summer. Thanks to 3D Systems' selective laser sintering (SLS) technology, 72 large-scale, lightweight 3D printed dragons were restored to The Great Pagoda after more than 230-year absence.

The Great Pagoda was designed by Sir William Chambers and completed in 1762 as a gift for Princess Augusta, the founder of the botanic gardens at Kew. In the years following the Pagoda’s unveiling, it drew crowds who came to marvel at the striking 163-foot structure and its exotic and eye-catching details – including the painted wooden dragons that adorned the octagonal corners of each successive level. In the 1780s, the dragons were removed to accommodate roof repairs but for some reason they were never replaced. Although rumors allege the dragons served as payment for royal gambling debts, experts believe the wood had simply rotted over time.

The Great Pagoda at Kew has become a UNESCO World Heritage site and needed major restoration. Historic Royal Palaces (HRP) took on the challenge of restoring the architectural treasure to its former glory. But bringing the dragons roaring back to life posed some particular problems in terms of design, quality, time, weight and cost. HRP required a solution that would authentically replicate the dragons, yet could withstand the famously inclement English weather. So HRP reached out to 3D Systems On Demand Manufacturing team, which uses Geomagic software, Selective Laser Sintering (SLS) 3D printing to create lightweight, durable replicas of the original dragons.

“We turned to 3D Systems to provide the rapid throughput, accurate details and excellent finishing that was needed for this project,” said Craig Hatto, project director, Historic Royal Palaces. “The engineering skill of 3D Systems’ team, the opportunity to light-weight the dragon statues, and the material longevity of SLS 3D printing were key considerations for this project.”

The project involved 3D scanning a wood-carved dragon with a FARO Design ScanArm into Geomagic Design X reverse engineering software. Using CAD allowed the team to add hidden features for mounting the dragons to the pagoda, as well as to make the dragons 60% lighter than wood alternatives. The significant weight reduction enabled by 3D printing ensures less stress is placed on this historic building. The CAD data also allows designers to scale the dragons and produce them in a variety of sizes from 1150mm to 1850mm in length.

“In 3D printing, we are not limited by the need or time required to wait for tooling,” said Nick Lewis, general manager, on demand manufacturing, 3D Systems. “The existence of digital 3D data gives us freedom to produce parts rapidly, and with custom sizes.”

The dragons were then printed on 3D Systems’ SLS (Selective Laser Sintering) machines in DuraForm PA, a durable polyamide 12 nylon material capable of producing a look and feel comparable to the original dragons. The 3D printed dragons were finished by 3D Systems’ skilled artisans who hand-painted each piece.

“We so often see 3D printing technology applied to new innovations that when we get the chance to literally make history, it is quite exciting,” said Phil Schultz, senior vice president and general manager, plastics and on demand manufacturing, 3D Systems. “In this collaboration with Historic Royal Palaces, we were able to bring new technology to bear on a historical landmark – restoring it to its former beauty and helping to ensure its future for generations to come. It’s a testament to the capabilities and expertise of our On Demand Manufacturing team. Our full suite of durable materials, 3D printing technologies, reverse engineering software and practical expertise allow us to create a custom solution no matter how unique the customer’s needs.”